The present invention relates to protective garments, such as shoe covers, having slip-resistant properties. As is generally known, protective garments, such as surgical gowns, surgical drapes, and shoe covers (hereinafter collectively xe2x80x9csurgical articlesxe2x80x9d) have been designed to greatly reduce or prevent the transmission through the surgical article of liquid and/or airborne contaminants. In surgical environments, such liquid sources include the gown wearer""s perspiration, patient liquids, such as blood, and life support liquids, such as plasma and saline. Examples of airborne contaminants include biological contaminants, such as bacteria, viruses, and fungal spores. Such contaminants may also include particulate material such as lint, mineral fines, dust, skin squamae, and respiratory droplets.
Many surgical articles were originally made from cotton or linen and were sterilized prior to use in the operating room. However, in many instances, surgical articles fashioned from cotton or linen provided insufficient barrier protection against airborne contaminants. Furthermore, these articles were costly, and of course, laundering and sterilization procedures were required before reuse.
Disposable surgical articles, which also may require sterilization prior to use, have largely replaced linen surgical articles. In some instances, such disposable surgical articles may be formed from nonwoven materials such as spunbond polypropylene or nonwoven laminates, such as spunbond/meltblown/spunbond laminates.
Some surgical articles, such as surgical gowns and drapes, are generally designed to loosely fit or overly the wearer. While surgical gowns and drapes are subjected to some pulling forces relative to the movement of the wearer, such gowns and drapes generally are not subjected to the load bearing forces or abrupt pulling or shearing forces to which more form-fitting surgical articles, such as shoe covers, may be subjected. As such, one challenge for designers of a fitted surgical articles is to sufficiently secure the seams in the fabric such that the article may withstand such load bearing, pulling, and shearing forces.
Additionally, in the case of shoe covers, it is not uncommon for the operating room floor or hospital floors, which are generally smooth by design, to become spotted with liquids that may be used or generated during a surgical procedure. As such, designers are further challenged to design a shoe cover that is both slip-resistant and cost effective. In the past, shoe covers were coated with a traction adhesive, such as a hot melt adhesive, to provide the shoe cover with slip-resistant properties. The traction adhesives were typically sprayed, coated, or printed on the shoe covers according to a particular pattern. Such adhesives have been found to be well-suited for use with shoe covers made from nonwoven polymeric laminates that by themselves provide limited traction. Unfortunately, since hot melt adhesives are somewhat tacky, the adhesives have a tendency to become coated with dust and other fine particulates over time. Once coated with such particles, the adhesives begin to lose much of their anti-slip characteristics. Further, hot melt adhesives also tend to contaminate the machines that are used to produce the shoe covers.
There is currently a need for a foot covering that has improved slip-resistant properties. More particularly, a need exists for a slip-resistant material for use on shoe covers that is less tacky than adhesives used in the past so that it will not collect dust and other particulates during use.
The present invention relates to a foot covering having a body shaped to surround a foot of a wearer, the body defining a bottom portion having an outside surface designed to contact the ground when the foot covering is being worn, and a slip-resistant material applied to the outside surface of the bottom portion, the slip-resistant material being an amorphous atactic olefin polymer. Any substantially amorphous atactic olefin polymer may be used, including polypropylene, polyethylene, or copolymers of propylene and ethylene. The polymer may have a broad molecular weight distribution, characterized by a polydispersity index of from about 4 to about 9. The polymer may be applied to the shoe cover according to various patterns.
The present invention also relates to a foot covering having a hollow body defining an opening for receiving a foot or a shoe, the hollow body being made from a nonwoven material, the body defining a bottom portion having an outside surface designed to contact the ground when the foot covering is being worn, and a slip-resistant material applied to the outside surface of the bottom portion. The slip-resistant material may be substantially amorphous atactic olefin polymer, including polypropylene, polyethylene, or copolymers of propylene and ethylene.
The present invention further relates to a foot covering having a body shaped to surround a foot of a wearer, the body defining a bottom portion having an outside surface designed to contact the ground when the foot covering is being worn, and a slip-resistant material applied to the outside surface of the body, the slip-resistant material being a copolymer of propylene and 1-butene. The present invention also contemplates use of terpolymers containing propylene, ethylene, and 1-butene. Additionally, any terminally unsaturated olefin such as 1-hexene or 1-octene may be copolymerized and used with the present invention.
The present invention includes a method of imparting slip-resistant properties to a foot covering including providing a foot covering having a body shaped to surround a foot of a wearer, the body defining a bottom portion having an outside surface designed to contact the ground when the foot covering is being worn, and applying a slip-resistant material to the outside surface of the body. The slip-resistant material may include a substantially amorphous atactic olefin polymer, for example, a copolymer of ethylene and propylene having from about 5% to about 15% percent ethylene by weight.
The present invention also includes a method of making a slip-resistant shoe cover including providing a body shaped to surround a foot of a wearer, the body defining a bottom portion having an outside surface designed to contact the ground when the shoe cover is being worn, and applying a slip-resistant material to the outside surface of the bottom portion. The slip-resistant material may include a copolymer of propylene and a terminally unsaturated olefin, for example 1-butene, 1-hexene, and 1-octene.
The present invention further includes a method of making a slip-resistant shoe cover including providing a body shaped to surround a shoe or a foot, the body defining a bottom portion having an outside surface designed to contact the ground when the shoe cover is being worn, and applying a slip-resistant material to the outside surface of the bottom portion. The slip-resistant material may include a substantially amorphous atactic olefin copolymer of ethylene and propylene, the polymer having a density of from about 0.8 grams per cubic centimeter to about 0.95 grams per cubic centimeter and having a polydispersity index of from about 4 to about 9.